Sometime you might have custom role, let’s say co-editor, setup using members plugin in your WordPress.  And then you want to achieve  showing all comments only to the user who has administrator role but user with co-editor role sees only some of the comment.  You could use the below code to overcome this saturation.

function custom_comments_clauses( $pieces ) {
// check role here
if( is_admin() && (!current_user_can( 'administrator' ) ) && current_user_can( 'co_editor' ) ) {
// add your own query here
$pieces['where'] .= " AND comment_post_ID IN ( //add your own query here )";
}
return $pieces;
}

//plug to this filter
add_filter( 'comments_clauses', 'custom_comments_clauses', 10, 1 )

Sometime you might have custom role, let’s say co-editor, setup using members plugin in your WordPress.  And then you want to achieve  showing all posts only to the user who has administrator role but user with co-editor role sees only some of the posts.  You could use the below code to overcome this saturation.

function custom_post_where( $where ) {
     if( is_admin() && ( !current_user_can('administrator') ) && ( current_user_can('co_editor') ) ) {
         // get current user
         global $current_user;
         get_currentuserinfo();
         $user_id = $current_user->ID;

         // you can add your own query here, something like this
         $where .= " AND ID IN (SELECT ID FROM $wpdb->posts WHERE post_author = $user_id)";
     }
     return $where;
}

// plug to this filter
add_filter( 'posts_where', 'custom_post_where' );

function add_more_profile_fields( $profileuser ) {
           //add your fields here
}

//call this action hook
add_action( 'show_user_profile', add_more_profile_fields );
add_action( 'edit_user_profile', add_more_profile_fields );

This above code is just adding additional fields to the profile page but we still need to do our own saving and error handling. Here we go,

function more_profile_fields_update( &$errors, $update, &$user ) {
      if($update) {
           // do the error handling here
           if($_POST['job_field'] == null) {
                $errors->add('job_field', '<strong>ERROR</strong>: Job field cannot be empty.', array('form-field' => 'job'));
           }
           else {
                //no error, let's save it here
                update_user_meta($user->ID, 'job_field', $_POST['job_field']);
           }
      }
 }

// hook it to this
add_action('user_profile_update_errors', 'more_profile_fields_update', 10, 3);

 if(preg_match('#' . basename(__FILE__) . '#', $_SERVER['PHP_SELF'])) { die('You are not allowed to call this page directly.'); }
 

### Validate country code, area code and phone number

 $intisd=$_POST["txtcountrycode"];
 $intccode=$_POST["txtareacode"];
 $intphone=$_POST["txtphone"];

if(substr_count($intisd,"+")>0){
 if(strpos($intisd,"+")==0)
 $intisd=substr($intisd,1,strlen($intisd));
 }

if($intisd != NULL){
 $result=ereg("^[0-9]+$",$intisd,$trashed);
 $result=ereg("^[0-9]+$",$intisd,$trashed);
 if(!($result)){$errors[] = "Please enter valid country code.";}
 }
 if($intccode != NULL){
 $result=ereg("^[0-9]+$",$intccode,$trashed);
 if(!($result)){$errors[] .= "Please enter valid area code.";}
 }
 if($intphone != NULL){
 $result=ereg("^[0-9]+$",$intphone,$trashed);
 if(!($result)){$errors[] .= "Please enter valid phone number.";}
 }
 

Cheers!

Cheers!

Features
1. Control voting feature via voting on/off (admin feature)
2. Control allow or disallow post author to vote his own posts (admin feature)
3. Control allow or disallow public voting (admin feature)
4. Customise vote and voted text (admin feature)
5. Customise vote and voted buttons images (admin feature)
6. Customise alert message for non logged in users (admin feature)
7. Voting logs for site administrator (admin feature)
8. Sort voting logs by vote count or voted date (admin feature)
9. Show current vote count and vote button on frontend templates
10. Compitible with almost all of the themes. You just need to call required function from your template
11. Total vote count widget
12. Top voted widget
13. Now public voting supported.
14. Now shortcode supported. e.g. [wpvoting]
15. Top voted posts list shortcode

Features in future releases
1. Export to CSV for admin voting logs
2. Registered user voting logs
3. Re-implement backend voting log list with WP_List_Table class

Installation
1. Upload `wpv-voting` folder to `/wp-content/plugins/` directory
2. Activate the plugin through the ‘Plugins’ menu in WordPress
3. Go to Voting menu >> Voting Options and turn on the voting feature
4. You may add the custom alert message for non logged in users
5. You can use shortcode `[wpvoting]` directly in your posts content < OR >
6. Add

 if(function_exists('wpv_voting_display_vote'))
 wpv_voting_display_vote(get_the_ID()); 

between the wordpress loop of your theme templates such as category.php or single.php
7. You may also use shortcodes or widgets

Shorcode Usage

– Vote button –

[wpvoting]

– Top voted –

[wpv-top-voted show="10" nopostmsg="Nothing to show!"]

Note: This plugin will create two tables in your wordpress database

FAQ
Q: Where all of my voting logs gone after I deactivated and reactivated the plugin?
A: This plugin’s uninstall function removes two tables which were created during plugin activation.

Q: Why that two tables need to be deleted during deactivation?
A: Because it is good for those people like who really want to completely remove the plugin from their CMS.

Q: So how can I record the voting logs before I deactivate the plugin?
A: In the next release, I will add export to csv feature to record the voting logs.

Q: Why I cannot vote even I am a logged in user?
A: Because the site admin disallowed post author to vote his own posts and the post what you are intended to vote might be your own post .

Q: How do I style the widgets to blend them into my theme?
A: You could use custom css feature which is on the voting options page to style the widgets.  For more information, please see the help section of the plugin option page (voting options page)

Changelog
1.0
The first release of the plugin

1.1
Fixed broken images

1.2
Added allow or disallow post author to vote his own posts feature

1.2.1
Fixed voting on/off options not getting selected state after initial plugin activate
Fixed allow post author to vote his own posts options not getting selected state after initial plugin activate
Fixed allow post author to vote his own posts options not getting deleted after deactivate the plugin

1.3
Added custom vote text feature
Added custom voted text feature
Added custom vote button feature
Added custom voted button feature

1.4
Added shortcode support
Tested compability with WordPress 3.2.1

1.4.1
Fixed admin css

1.4.2
Added rest all voting

1.5
Added total vote count widget
Re-design admin voting options page

1.5.1
Added db version to options tbl for next release (public voting)

1.6
Added public voting feature (unregistered / non-logged in users voting)

1.7
Added top vote widget
Add safe-guard javascript pop-up confirmation box for “Reset All” button
Implemented proper un-installation (Now deactivate won’t delete db tables and settings)
Bug fix (two or more users voting from same computer can’t vote)

1.8
Added top voted list shortcode
Added wpv_voting_get_display_vote function to overcome vote button is keep showing at the top of the post
Now wpv_voting_display_vote will just echo out the wpv_voting_get_display_vote return
Vote button implementation is moved to wpv_voting_get_display_vote
Fixed vote button is keep showing at the top of the post when user uses [wpvoting] shortcode
Fixed minor CSS rule
Fixed minor spacing issue in javascript

Download

Note: Kindly please rate this plugin or vote the compatibility whatever this plugin is working for you or not. So I could review it and improve the quality of this plugin. Appreciate your help!

Resources
http://www.garyc40.com/2010/03/5-tips-for-using-ajax-in-wordpress/
http://www.onextrapixel.com/2009/06/22/how-to-add-pagination-into-list-of-records-or-wordpress-plugin/
http://www.onextrapixel.com/2009/07/01/how-to-design-and-style-your-wordpress-plugin-admin-panel/
http://planetozh.com/blog/2009/09/top-10-most-common-coding-mistakes-in-wordpress-plugins/
http://wordpress.org/extend/plugins/vote-it-up/
http://wordpress.org/extend/plugins/shortcodes-ultimate/